The present invention relates to an in-vehicle mount type navigation device which is mounted in a vehicle and displays both of a road along which the vehicle runs and its periphery, and more particularly to an in-vehicle mount type navigation device through which one obtains a guide route for guiding the vehicle to a destination.
There has been hitherto known an in-vehicle mount type navigation device which calculates the current position of a vehicle running on a road to display the current position on a screen of a liquid crystal display device or the like and also displays a guide route along which the vehicle should run to a destination. In this system, the current position of the vehicle is calculated on the basis of both of the travel direction of the vehicle measured by an azimuth sensor such as gyro or the like and the travel distance of the vehicle measured by a vehicle speed sensor or distance sensor. The travel distance of the vehicle is generally calculated by measuring the revolutions per predetermined travel interval of the output shaft of a transmission or the like and multiplying the revolutions per predetermined travel interval thus measured by a distance coefficient corresponding to the travel distance of the vehicle per one revolution of a tire.
Further, Japanese Laid-open Patent Application Sho-63-148115 has disclosed a technique of correcting an error of the current position calculated on the basis of the travel direction and travel distance of the vehicle thus obtained. According to this technique, an estimation position of a vehicle is calculated on the basis of the travel distance and the azimuth (direction) variation amount of the vehicle, and an error amount is gained on the basis of the error of a road map. Thereafter, in association with each of all the roads located within the range of the error amount with the estimation position of the vehicle at the center thereof, positions on each of the roads are registered as self-positions. The correlative coefficients of these self-positions thus registered to each road are calculated, and the self-position associated with the correlative coefficient which shows the minimum error to the roads is set as the current position of the vehicle. An image obtained by superposing a mark indicating the current position thus obtained (for example, an arrow) and a map corresponding to map data stored in a CD-ROM is displayed on the screen of the liquid crystal display device.
As described above, the in-vehicle mount type navigation device is provided with a function of setting a destination, determine a route extending from the current position to the destination by using Dijkstra""s Algorithm or the like and guiding the vehicle along the route thus determined. Recently, there has been proposed an in-vehicle mount type navigation device in which not only a final destination, but also one or two places through which a route extending to the destination passes (hereinafter referred to as xe2x80x9cvia-placexe2x80x9d) can be set to determine a guide route passing through the via-place(s) to the destination.
However, the conventional navigation device has a problem that once a predetermined number of (one or two) via-places and destinations are set, the alteration thereof is difficult. That is, although it is possible to change a place set as a via-place to another place and change a place as a destination to another place, it is difficult to alter the destination to a via-place or add a new via-place.
Further, there is also a problem that a cumbersome operation must be carried out to set the destination for searching a route.
Therefore, a first object of the present invention is to provide an in-vehicle mount type navigation device with which a user can freely set a destination and via-places through which a route extending to the destination passes.
A second object of the present invention is to provide an in-vehicle mount type navigation device which can search a route to a desired destination without needing any cumbersome operation.
In order to attain the first object of the present invention, an in-vehicle mount type navigation device including map data read-out means for reading out map data from a road data storing medium in which data on a map containing roads and names of respective places are stored, current position calculating means for calculating a current position of a vehicle, display means for displaying the map and the current position of the vehicle, and guide route calculating means for calculating a guide route to the settled destination by referring to the map data, further including:
destination/via-place storing means for storing data representing the destination and via-places through which the route to the destination passes;
position specifying means for specifying any position between a via-place and another via-place or between a via-place and a destination, or any position next to the destination;
place specifying means for specifying a place to be added to the position specified by the position specifying means; and
destination/via-place control means for storing the data representing the place specified by the place specifying means into the destination/via-place storing means in association with the position specified by the position specifying means,
wherein on the basis of the data stored in the destination/via-place storing means, the guide route calculating means calculates a guide route which successively passes through the via-places and finally reaches the destination.
According to the present invention, the data on a place to be newly added to a position specified by the position specifying means is written as a via-place or destination into the destination/via-place storing means, thereby obtaining a guide route which passes through or reaches the via-place or the destination thus newly added.
Accordingly, a driver can freely set the via-place and the destination to be guided along the guide route.
In the present invention, an image containing a list in which the via-places and/or the destination are described in passage order and a list in which the position between the via-places or between the destination and the via-place or the position next to the destination are specified may be generated on the basis of the data stored in the destination/via-place storing means by the position specifying means, and the image may be displayed by the display means.
Further, the data representing the points of the via-places and/or the destination may be stored into the destination/via-place storing means by the destination/via-place control means while these points are associated with the passage order thereof, and the point which is associated with the largest number of the passage order is settled as the destination.
In response to an instruction indicating as the destination the center position of a map displayed on the display means, the data representing the center position may be stored as data representing the destination into the destination/via-place storing means by the destination/via-place control means, and the data which are previously stored as the destination may be set as a via-place located just before the destination.
Through the above operation, a new destination can be added without performing any operation of searching the name of a place or the like.
In order to attain the above second object of the present invention, an in-vehicle mount type navigation device including map data read-out means for reading out map data from a road data storing medium in which data on a map containing roads and names of respective places are stored, current position calculating means for calculating a current position of a vehicle, display means for displaying the map and the current position of the vehicle, and guide route calculating means for calculating a guide route to the settled destination by referring to the map data, further including: registration place specifying means for specifying some of registration places corresponding to points which are beforehand registered, wherein the guide route calculation means sets the registration place thus specified as a destination to calculate a guide route extending to the destination.